Traditionally, astronomy has been on the forefront of using computer-based tools and systems; in particular, astronomical publishers developed and implemented new publishing procedures well ahead of publishers in other disciplines (see for instance Boyce and Dalterio, 1996). Astronomy librarians too are enhancing their services to make most efficient use of the electronic environment. While our mission, namely to fulfill the information needs of our institute's scientists and engineers, has not changed, our approach in order to accomplish this mission is changing.
In addition to physical libraries at our institutes, we now maintain virtual libraries on the world-wide-web which provide access to the most important information resources. A paradigm shift takes place from libraries as collectors of items to libraries as facilitators of access to all kinds of information, provided by anybody, located anywhere in the world, accessible at any time. Librarians have always been the link between resources available in-house and those that had to be obtained from elsewhere, but never before have external resources been so easily accessible, not only by librarians, but also by our users. Virtual libraries are characterized by an ever decreasing border between internal and external resources; crossing this border often is only noticeable in a difference in access speed and, ideally, even this difference will vanish eventually.
Because of this strong focus on electronic resources, libraries must pay utmost attention to their appearance on the web. Increasingly, users visit our web pages instead of reading the printed brochure if they seek information about our library - the homepage has become our business card. This is the place to show users the range of services, to provide them with starting points for their information search and to encourage them to contact us for more detailed questions. As users typically don't spend much time on pages which require a lot of reading to be understood, virtual libraries must be clearly laid out and self-explanatory.
Appealing designs are just the immediately visible part of virtual libraries. What really counts are the contents and the service we provide. In the information-rich Western world, information overload is a more severe problem than lack thereof. To create and maintain well-structured library web pages means to put important resources in context by monitoring existing and evolving information systems, selecting the useful ones and arranging them according to their contents.
Many users will find their way to information resources without guidance from librarians, but others will appreciate our assistance. In these cases, prompt responses to enquiries should be a matter of course. From our own experience, we know too well that many companies maintain colorful web pages, but messages from customers just seem to be swallowed by "black holes" and never get any reply. Such an experience is at best annoying for clients and damages the image of the company. Libraries are service entities par excellence and should give highest priority to prompt and reliable delivery of information.
Of course we don't have to be passive, waiting for users to request our service. The internet provides us with tools to easily distribute information. Latest developments and announcements can be reported through short, informative e-mail messages which usually produce only a minimal interruption for astronomers. The same information can also be posted in the news section of the library's web pages, but it seems that many users prefer push (sent to their mailbox) over pull (they have to actively solicit information from a web page) services. We also can, and should, actively seek communication with scientists to learn about their way of working, their concerns and their suggestions for improvement (Cummins, 1998). Surveys among users may be appropriate to measure user satisfaction; this means must be used very carefully though as scientists typically receive far too many questionnaires so that they may not be willing or able to respond. Active "advertising" of the library usually results in valuable feedback and enhanced communication between users and librarians; such presentations can include talks at faculty meetings, semi-formal meetings with astronomers, guided library tours, or contributions to the institute's newsletter. Scientists may appreciate brief training sessions on usage of information systems, in particular instructions tailored to meet the needs of remote users at the telescopes. Anything that increases the visibility of the library will be helpful and worth trying.
On a broader scale, communication between librarians and the International Astronomical Union is of immense value to emphasize the rôle of libraries. In the beginning of the year 2000, Brenda Corbin, U.S. Naval Observatory, was the first librarian to become a full member of the IAU, an unprecedented honor and recognition of years of active participation on IAU Commissions. Her successful application will open the possibility of joining IAU to other librarians and lead to an even closer cooperation.